Check it out if it takes pictures while keeping the AF on button down. I bet you will see no pictures being taken. But you have to keep pressing the AF on button.

Now release the AF on button. It will rattle off whether in or out of focus. Even with the lens cap on. Why ? Because in this mode releasing the af on button is interpreted as 'in focus' by the camera. So pressing the release button will let the camera take the picture.

Remember, first try it with AF on only activated and keep it pressed down while at the same time pressing the release button!

Try it and report back.

lock

I know what you are trying to say but, here is the thing. Just because the D800 thinks something is in focus; doesn't make it so. It loves back and front focus and just plain missing by miles unless there is a heap of contrast (more than the D3s needs etc).

...and my experience is that the D800 AF is far superior to the D300s. The D800 simply wins in EVERY situation.

When D800 AF is superior to D700 so I can't wait to get this camera With my D700 I have every single shot in focus and I have focus priority set to release It's only my fault when I haqve some motion blur on photo, but AF on my D700 never misses even in very dark light conditions. When D800 is even better I will be blowed away, but I'm still waiting if Nikon releases body between D600 and D800, more closer to D700 Something like D600 with D800 AF and body